Centuries of development in optics have given us passive devices (i.e. lenses, mirrors and filters) to enrich audience immersivity with light effects, but there is nothing similar for sound. Beam-forming in concert halls and outdoor gigs still requires a large number of speakers, while headphones are still the state-of-the-art for personalized audio immersivity in VR. In this work, we show how 3D printed acoustic metasurfaces, assembled into the equivalent of optical systems, may offer a different solution. We demonstrate how to build them and how to use simple design tools, like the thin-lens equation, also for sound. We present some key acoustic devices, like a “collimator”, to transform a standard computer speaker into an acoustic “spotlight”; and a “magnifying glass”, to create sound sources coming from distinct locations than the speaker itself. Finally, we demonstrate an acoustic varifocal lens, discussing applications equivalent to auto-focus cameras and VR headsets and the limitations of the technology.